Fountain pen barrel



June 16, 1936.

FOUNTAIN PEN BARREL Filed April 11, 1935 Allan F. Odell INVENTOR.

v #4. Law

ATTORNE A. F. ODELL. 2,044,181

Patented lune 16, 1936 was a gram FOUNTAIN PEN BARREL Allan F. Odell, Upper Montclair, N. 31., assignor to Du Pont Viscoloid Company, Wilmington, DeL, a corporation of Delaware Application April 11,

Glaims.

This invention relates to fountain pen barrels and, more particularly, relates to fountain pen barrels of the type used in sackless fountain pens,

said barrels having on their inner surface a thin 5 coating which is resistant to penetration, discoloration, and attack by inks.

Heretofore the barrels of self filling fountain pens of the sackless type have usually been made of a cellulose nitrate plastic. This plastic may be formed into rods and then drilled for tubes, the interior of the tubing being smoothed to a certain extent by reaming, which nevertheless leaves the surface somewhat rough. Alternatively, the tubing may be formed by winding strips of sheet 1.3 plastic on to a mandrel. The tubing may be wholly or partially made of transparent plastic so that, in the finished product, the level of the ink may be determined by holding the barrel up to the light.

The interior surface of the barrel, when the barrel is made of a cellulose ester plastic, is subject to attack by inks, causing a roughening of the surface upon which thereafter a deposit of ink residue is retained, resulting in a loss in transparency of the pen barrel.

An object of the present invention is to provide a fountain pen barrel adapted to serve as an ink reservoir and having, on the inner surface thereof, a thin smooth coating which will be resistant to attack by ink. A further object is to provide such a barrel, wholly or partially transparent, which will maintain its transparency so that, even after a long period of use, the level of ink may be determined by subjecting thebarrel to transmitted light. Other objects of the invention will be apparent'from the description given hereinafter.

These objects are accomplished according to the present invention by coating the inner'surface of a fountain pen barrel, which ordinarily would be at least partially transparent, with a liquid composition containing a water-insoluble cellulose ether.

This may be done by any conventional method of coating, by dipping the barrel into a. liquid coating composition containing the water-insoluble cellulose ether, by swabbing the coating on to the inner surface of the barrel, or by spraying the liquid coating composition on to the inner surface of the barrel.

In the accompanying drawing, the single figure is a perspective view of a fountain pen with parts broken away to illustrate a specific embodiment of the present invention.

Referring to the figure, reference numeral I indicates generally a fountain pen made of a cellu- 1935, Serial No. 15,829

lose ester plastic, cellulose nitrate or acetate being commonly employed for this purpose. Preferably the barrel is at least partially transparent so the level of the ink therein can be seen when the barrel is held up to the light. This barrel l is provided on its interior surface with a coating 2, the thickness of which has been exaggerated for purposes of illustration. This coating 2 is a water-insoluble cellulose ether.

In the following examples are illustrated specific coating compositions adapted for use in the present invention:

Example 1 Ethyl cellulose 60 grams Ethyl acetate 200 cc. Ethyl alcohol (95%)-"; 800 cc. Acetone 200 cc. Toluene 50 cc.

Example 2 Ethyl cellulose 120 grams Ethyl acetate 200cc. Ethyl alcohol (95%) 800 cc. Acetone 200 cc. Toluene 50 cc.

Example 3 Butyl cellulose 60 grams Methyl formate 400cc. Ethyl alcohol (95%) 850cc.

Example 4 Benzyl cellulose 120 grams Ethyl acetate 100 cc. Ethyl alcohol (95%) 1000 cc. Acetone 50 cc. Benzol 100cc As illustrated in the following example, natural or synthetic resins such as coumaron resin, dammar gum, or copal gum, may be added to the coating composition:

Example 5 Ethyl cellulose 60 grams Coumaron resin (132) 60 grams Toluene a 1260 cc. Ethyl alcohol (95%) 66cc. Ethyl acetate 663 cc.

As will be understood by those skilled in the art,

the proportion of cellulose ether to solvent may be widely varied and will be determined, to a great extent, by the consistency of the coating composition desired, thickness of the film to be deposited, and the like. As illustrated in the specific examples, the widest variation of solvents and solvent combinations may be used, as will be fully understood by the art.

An advantage of the present invention is that the application of the water-insoluble cellulose ether coating to the inner surface of the pen barrel gives a smooth surface in the barrel, thus decreasing the tendency for retention of ink residues on the surface and, further, this coating protects the barrel of cellulose ester plastic, usually cellulose nitrate plastic, from attack by inks. With a partially or wholly transparent barrel, the coating thus effects a maintenance of transparency of the barrel so that the level of the inkv in the barrel may be readily determined even after the pen has contained ink for long periods of time.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

I claim: 1. A fountain pen barrel made of a cellulose ester plastic having an interior coating of a "water-insoluble cellulose ether.

2. A fountain pen barrel made of a cellulose ester plastic, which barrel is at least partially transparent for the purpose of indicating the ink level, said barrel having on its inner surface a coating of a water-insoluble cellulose ether.

3. A fountain pen barrel made of a cellulose ester plastic, which barrel is at least partially transparent for the purpose of indicating the ink level, said barrel having on its inner surface a coating of ethyl cellulose.

4. A fountain pen barrel made of a cellulose nitrate plastic, which barrel is at least partially transparent for the purpose of indicating the ink level, said barrel having on its inner surface a. coating of a water-insoluble cellulose ether.

5. A fountain pen barrel made of a cellulose nitrate plastic, which barrel is at least partially transparent for the purpose of indicating the ink level, said barrel having on its inner surface a coating of ethyl cellulose.

ALLAN F. ODELL. 

